Recent Progress and New Challenges in Isospin Physics with Heavy-Ion Reactions

Relativistic continuum Hartree Bogoliubov theory for ground-state properties of exotic nuclei

Reaction dynamics with exotic nuclei

Curved pi-conjugation, aromaticity, and the related chemistry of small fullerenes (< C60) and single-walled carbon nanotubes.

Spherical Aromaticity: Recent Work on Fullerenes, Polyhedral Boranes, and Related Structures†

A new carbon solid made of the world's smallest caged fullerene C-20

Measurement of reaction cross section for proton-rich nuclei ( A< 30) at intermediate energies

Here we report the observation of a linear carbon-atom chain, synthesized using an arc discharge from a graphite double anode. We use high-resolution TEM to evidence the formation of a carbon-atom chain along the axis of a needlelike structure consisting of concentric cylindrical graphitic shells. The atomic chain in the core of the innermost cylinder, by calculations on the basis of van der Waals interactions, demonstrates an extremely high thermal stability (up to 4200 K) and exhibits high mechanical strains.

Carbon-atom chain formation in the core of nanotubes

Reaction cross section sigma(R) of proton-rich isotones (N = 10) near Al-23 and Al isotopes (Al23-28) on C target have been measured at intermediate energies around 30 MeV/nucleon. An abnormal increase of the experimental sigma(R) is observed for Al-23 and it suggests that there is an anomalously large matter rms radius in Al-23. Together with the very weakly binding of the last proton (S-p = 0.125 MeV), it indicates that there is a proton halo in Al-23. This conclusion is also supported by the difference factor d which is deduced from the measured and theoretical sigma(R) in the Glauber or Boltzmann-Uehling-Uhlenbeck model and is used for the manifest of halo phenomena. The theoretical calculation based,on the relativistic density dependent Hartree model shows that there is a proton halo when the last proton is in the 2s(1/2) orbit in Al-23. The significance of the proton halo in Al-23 is discussed.

Existence of a proton halo in Al-23 and its significance

Within the framework of an isospin-dependent quantum molecular dynamics model. the multifragmentation in reactions of Sn-112+Sn-112 and Sn-124+Sn-124 at 40 MeV/nucleon is investigated. The calculated results are in good qualitative agreement with the experimental data which indicated that there were significantly different scalings of the mean number of intermediate mass fragments with the number of neutron and charged particles between the two reaction systems. Meanwhile, it is shown that the preequilibrium emission may affect strongly these scalings. [S0556-2813(99)05911-7].

Zhi-Yuan Zhu

Papers

A new carbon solid made of the world's smallest caged fullerene C-20

Measurement of reaction cross section for proton-rich nuclei ( A< 30) at intermediate energies

Carbon-atom chain formation in the core of nanotubes

Existence of a proton halo in Al-23 and its significance

Isospin dependence of nuclear multifragmentation in Sn-112+Sn-112 and Sn-124+Sn-124 collisions at 40 MeV/nucleon